U.S. patent application number 10/058055 was filed with the patent office on 2002-08-01 for sheet processing apparatus and image forming apparatus.
Invention is credited to Iwama, Satoshi, Nonaka, Masato.
Application Number | 20020101021 10/058055 |
Document ID | / |
Family ID | 18887183 |
Filed Date | 2002-08-01 |
United States Patent
Application |
20020101021 |
Kind Code |
A1 |
Nonaka, Masato ; et
al. |
August 1, 2002 |
Sheet processing apparatus and image forming apparatus
Abstract
A sheet processing apparatus for processing a sheet bundle
includes a stitching unit having a head portion for driving staples
into the sheet bundle and an anvil portion for receiving and
bending the staples driven by the head portion, a feeding device
for feeding the sheet bundle to a stitching position between the
head portion and the anvil portion, a transport device for
transporting the stitching unit to a position perpendicular to a
sheet bundle feeding direction, a guide member for guiding the
sheet bundle to the stitching position, and a supplement guide
member. The supplement guide member retracts to a position that
does not hinder the movement of the stitching unit when the
stitching unit moves, and guides the sheet bundle to the guide
member without a leading edge of the sheet bundle touching the
upstream edge of the guide member.
Inventors: |
Nonaka, Masato; (Abiko-shi,
JP) ; Iwama, Satoshi; (Yamanashi-ken, JP) |
Correspondence
Address: |
KANESAKA AND TAKEUCHI
1423 Powhatan Street
Alexandria
VA
22314
US
|
Family ID: |
18887183 |
Appl. No.: |
10/058055 |
Filed: |
January 29, 2002 |
Current U.S.
Class: |
270/58.08 |
Current CPC
Class: |
B65H 31/3027 20130101;
B42C 1/12 20130101; B65H 2408/125 20130101; B65H 2404/742 20130101;
B65H 2301/42262 20130101; B65H 2404/741 20130101; B65H 2408/1222
20130101 |
Class at
Publication: |
270/58.08 |
International
Class: |
B65H 033/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2001 |
JP |
2001-021663 |
Claims
What is claimed is:
1. A sheet processing apparatus for processing a sheet bundle,
comprising: a stitching unit including a head portion for driving
staples into the sheet bundle, and an anvil portion for receiving
and bending said staples driven by the head portion and facing said
head portion; feeding means for feeding the sheet bundle to a
stitching position between the head portion and the anvil portion
in the stitching unit; transport means attached to the stitching
unit for transporting the same to a position perpendicular to a
sheet bundle feeding direction; a guide member disposed between the
head portion and the anvil portion for guiding the sheet bundle to
the stitching position; and a supplement guide member disposed at
an upstream side of the guide member in the sheet bundle feeding
direction, said supplement guide member being able to retract to a
position that does not hinder movement of the stitching unit when
the stitching unit moves, and guiding the sheet bundle to the guide
member without a leading edge of the sheet bundle touching an
upstream edge of the guide member in the sheet bundle feeding
direction when the sheet bundle is fed to the stitching
position.
2. A sheet processing apparatus for processing a sheet bundle
according to claim 1, wherein said supplement guide member has an
inclined contact portion abutting against the stitching unit so
that the supplement guide member retracts when the stitching unit
moves.
3. A sheet processing apparatus for processing a sheet bundle
according to claim 2, wherein said stitching unit has a roller
abutting against said contact portion.
4. A sheet processing apparatus for processing a sheet bundle
according to claim 1, wherein said supplement guide member is
disposed on the stitching unit so that when the stitching unit
moves to a predetermined position, the supplement guide member
retracts to a position that does not interfere with a movement of
the stitching unit.
5. A sheet processing apparatus for processing a sheet bundle
according to claim 1, further comprising: aligning means situated
adjacent to the stitching unit for aligning a side of the sheet
bundle perpendicular to the sheet bundle feeding direction; and
control means connected to the transport means for controlling the
same so that a position of the supplement guide member is changed
based on at least one of an aligning reference of said aligning
means and a sheet size.
6. An image forming apparatus comprising: an image forming unit;
and a sheet processing apparatus attached to the image forming unit
for processing a sheet bundle having sheets with images formed by
the image forming unit, said sheet processing apparatus being
formed according to claim 1.
Description
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
[0001] The present invention relates to a sheet processing
apparatus and an image reading apparatus, in particular it relates
to an apparatus for performing a sheet bundle binding process.
[0002] Conventionally, an image forming apparatus such as a copier,
a printer, a facsimile machine and other devices that combine them
have a sheet processing apparatus that stacks a bundle of sheets
discharged from the image forming apparatus and staples (binding
process) the bundle.
[0003] Some of such apparatuses are provided with a stitching unit
comprising a head to drive staples and an anvil to receive and bend
the staples to bind a bundle of sheets substantially in a center
area thereof.
[0004] An example of such a sheet processing apparatus, as
disclosed in Japanese Patent Publication 07-157180, has a partial
guide attached directly to a head and an anvil to guide a bundle to
pass between them.
[0005] Nonetheless, in a conventional sheet processing apparatus,
the guide is extended traversing a moving direction of a bundle
when a bundle passes through a transport path between the head and
the anvil. The guide also extends parallel to the bundle surface
opposite to the head and anvil, i.e. a width direction of the
bundle. In this case, it is not possible to guide and support the
bundle completely across its width direction. Therefore, an edge of
the bundle in the width direction tends to droop down or get caught
on other internal parts upon transporting or stitching. As a
result, an accurate positioning of the bundle is obstructed,
causing undesirable stitching.
[0006] If a guide is attached substantially across an entire region
in a width direction of the bundle, it is possible to guide and
support the bundle throughout the entire width direction. But a
leading edge of the bundle is easy to get caught in a gap between
the head, the anvil and the guide, causing inaccurate positioning
of the bundle and improper binding of the bundle.
[0007] An object of the present invention, in view of the problems
of the current technology, is to provide a sheet processing
apparatus and an image reading apparatus that securely transports
and properly stitches a bundle.
[0008] Further objects and advantages of the invention will be
apparent from the following description of the invention.
SUMMARY OF THE INVENTION
[0009] The present invention provides a sheet processing apparatus
comprising a stitching unit having a head to drive staples into a
bundle of sheets and an anvil to receive and bend the staples
driven from the head. When the bundle is to be stitched, the
stitching unit moves perpendicular to a direction that the bundle
is transported. The sheet processing apparatus according to the
present invention also comprises a guide member attached between
the head and the anvil to guide the bundle to a stitching position,
and a supplement sheet guide member disposed upstream side of the
guide member in a transport direction of the bundle. The supplement
sheet guide will not contact a leading edge of the bundle, and
retracts so that the supplement sheet guide does not hinder
movements of the stitching unit when the stitching unit moves.
[0010] The supplement guide member can have an inclined contact
portion that touches the stitching unit. When the stitching unit
moves, the stitching unit abuts the inclined contact portion, and
the supplement guide unit retracts not to obstruct the movement of
the stitching unit.
[0011] In another aspect of this invention, the stitching unit has
a roller that contacts the inclined contact portion.
[0012] The supplement guide member may be disposed on an upstream
in a transport direction of the bundle where the supplement guide
does not interfere with the movement of the stitching unit upon
retracting.
[0013] The supplement guide member may be attached to the stitching
unit so that when the stitching unit moves to a predetermined
position, the supplement guide member retracts to a position where
the supplement guide member does not interfere with movements of
the stitching unit.
[0014] The sheet feeding apparatus of the invention can include an
aligning means to align in a direction traversing a transport
direction of the bundle; a moving means to move the stitching unit
in a direction traversing a transport direction of the bundle; and
a control means to control the moving means to adjust the position
of the supplement guide member.
[0015] One aspect of the present invention provides an image
forming apparatus comprising an image forming unit and a sheet
processing apparatus for stitching the bundle of sheets with images
formed by the image forming apparatus. The sheet processing
apparatus can be the one described in any of the aspects mentioned
above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a view for a copier that has an image forming
apparatus with a sheet processing apparatus according to the
present invention;
[0017] FIG. 2 is a side cross-section view of the sheet processing
apparatus in FIG. 1;
[0018] FIG. 3 is a top view of a processing tray of the sheet
post-processing apparatus in FIG. 1;
[0019] FIG. 4 is a front view of a stopper disposed in the sheet
processing apparatus in FIG. 1;
[0020] FIG. 5 is a front view of a stopper disposed in the sheet
processing apparatus in FIG. 1;
[0021] FIG. 6 is a perspective view of a saddle-stitching unit
disposed in the sheet processing apparatus in FIG. 1;
[0022] FIG. 7 is a view of an attachment block, a guide base block,
and a head housing of the saddle-stitching unit;
[0023] FIG. 8 is a processing diagram of the sheet processing
apparatus in FIG. 1;
[0024] FIG. 9 is a view of another attachment block, a guide base
block, and a head housing of the saddle-stitching unit in FIG.
7;
[0025] FIG. 10 is a view of a gap-detecting sensor disposed on the
stitching unit;
[0026] FIG. 11 is a view of a detecting operation of the
gap-detecting sensor in FIG. 10;
[0027] FIG. 12 is a top view of a transfer belt of the sheet
processing apparatus in FIG. 1;
[0028] FIG. 13 is a view of a home position of the saddle-stitching
unit in FIG. 7;
[0029] FIG. 14 is a front view of the saddle-stitching unit in FIG.
7;
[0030] FIG. 15 is a front view for the saddle-stitching unit in a
stitching position in FIG. 7;
[0031] FIG. 16 is illustrating a stopper operation of the sheet
processing apparatus in FIG. 1;
[0032] FIG. 17 is showing a relationship between a sheet bundle
position and a stopper that is returned to a limiting position;
[0033] FIG. 18 is a perspective view of a preguide disposed in a
transport guide;
[0034] FIGS. 19(a) through 19(c) show a retracting operation of the
preguide in FIG. 18 when the saddle-stitching unit moves; and
[0035] FIG. 20 is showing a sheet bundle folding operation of a
folding unit disposed in the sheet processing apparatus in FIG.
1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] Hereunder, embodiments of the invention will be explained
with reference to the accompanied drawings.
[0037] FIG. 1 shows a structure of a copier as an example of an
image forming apparatus with a sheet processing apparatus according
to an embodiment of the present invention.
[0038] In the drawing, the main body 1 of the copier 20 comprises a
platen glass 906 as a table for placing an original document, a
light source 907, a lens system 908, a sheet feeder 909, and an
image forming section 902. The main body 1 is provided with an
automated document feeder 940 for automatically feeding an original
document "D" to the platen glass 906. Additionally, a sheet
processing apparatus 2 is mounted on the main body 1.
[0039] The sheet feeder 909 has cassettes 910 and 911 attached to
the main body 1 for storing sheets of copy paper "S" and a deck 913
disposed on a pedestal 912. The image forming section (image
forming means) 902 has a cylindrical photosensitive drum 914.
Around the photosensitive drum 914, provided in the image forming
section 902 are a developer 915, a separation charger 917, a
cleaner 918, and a primary charger 919. At downstream of the image
forming section 902, there are a feeding apparatus 920, a fixing
device 904, and a pair of discharge rollers 1a and 1b.
[0040] Operations of the mechanisms inside the main body 1 of the
copier 20 will be explained next. When a paper feed signal is sent
from a control unit 921 disposed in the main body 1, the sheet "S"
is discharged from the cassettes 910 and 911, or the deck 913. The
light source 907 irradiates light to an original document "D"
placed on the platen glass 906. The light is reflected by the
document D and passed through the lens system 908 to a
photosensitive drum 914.
[0041] The photosensitive drum 914, pre-charged by a primary
charger 919, creates an electrostatic image thereon upon
irradiation of the light. The developer 915 develops the
electrostatic image to form a toner image. A resist roller 901
eliminates skew of the sheet of copy paper "S" fed from the sheet
feeder 909, and then adjusts a feeding timing to an image forming
section 902.
[0042] In the image forming section 902, the toner image on the
photosensitive drum 914 is transferred to the sheet of copy paper
"S". The sheet of copy paper "S" with the toner image is then
charged to an opposite polarity to the transfer electrode 916 by
the separating charger 917 to be separated from the photosensitive
drum 914.
[0043] The feeding apparatus 920 transports the sheet of copy paper
"S" to the fixing unit 904. The fixing unit 904 permanently fixes
the image on the sheet of copy paper "S". After fixing the image,
the sheet of copy paper "S" is discharged to the sheet processing
apparatus 2 from the main body 1 by a pair of the discharged
rollers 1a and 1b.
[0044] FIG. 2 is a side cross-section view of the sheet processing
apparatus 2. The sheet processing apparatus 2 is provided with a
pair of feed guides 3, a sheet-detecting sensor 4, a processing
tray 8, a saddle-stitching unit 30, and a folding unit 50. A pair
of the feed guides 3 receives a sheet discharged from a pair of the
discharge rollers 1a and 1b, and guides the sheet into the sheet
processing apparatus 2. The sheet-detecting sensor 4 detects the
sheet transporting in a pair of the feed guides 3.
[0045] The sheet-detecting sensor 4 determines a timing to align
and whether or not the sheet is jammed inside of the feed guide 3.
A pair of the discharge rollers 6 supports the sheet in the feed
guide 3 sandwiched therebetween.
[0046] The processing tray 8 receives and stacks sheets discharged
by a pair of the discharge rollers 6. A pair of aligning plates 9
is disposed on the processing tray 8 to guide and align both edges
of the sheet in a width direction perpendicular to the sheet bundle
transport direction.
[0047] Each of the aligning plates 9, as shown in FIG. 3, is
attached to a side edge of the processing tray 8 in a width
direction perpendicular to the sheet bundle transport direction.
Each of the aligning plates 9 has a rack 16 that engages a pinion
15 disposed on a shaft of one of aligning motors 14 comprising a
stepping motor disposed below the processing tray 8. The aligning
plates 9 move by an appropriate distance in the sheet transport
direction when the aligning motors 14 at a front side and a
backside rotate.
[0048] Depending on a type of copier that the sheet processing
apparatus is attached to, whether discharged sheets are aligned
based on a center or edges, the embodiment of the invention can
discharge sheets aligned at either a center of the sheets or
edges.
[0049] In FIG. 2, the feed guide 7 guides a sheet discharged from a
pair of the discharge rollers 6 into the processing tray 8. A
paddle 17 is disposed below the feed guide 7. The paddle 17, which
is made of a semicircular elastic rubber to secure grip, rotates
around a center of a shaft 17a and contact an upper surface of a
sheet.
[0050] The paddle 17 is also integrated with a fin 17b extending
radially from a center of the shaft 17a and a paddle surface 17c.
The paddle 17 deforms easily as sheets are stacked in the
processing tray 8 to apply adequate force to the sheets so that the
sheets can be transported properly.
[0051] The processing tray 8 has a first pulley 10 disposed on a
first pulley shaft 10a and a second pulley 11 disposed a second
pulley shaft 11a. A feed belt 12 is provided between the first
pulley 10 and the second pulley 11. A pressing pawl 13 is disposed
on the circumference of the feed belt 12.
[0052] The first pulley shaft 10a has a lower bundle feed roller 18
disposed thereon with the same axle. An upper feed roller 19 is
provided above the lower bundle feed roller 18, and moves between
one position (shown in a dotted line) where the upper feed roller
19 abuts the lower bundle feed roller 18 and another position
(shown in a solid line) separated from the lower bundle feed roller
18.
[0053] A stopper 21 shown in FIG. 2 has a single stopper plate 421
extended in a width direction of the sheet as shown in FIG. 4. A
pair of the discharge rollers 6 discharges a sheet, then the sheet
drops by its own weight into the processing tray 8. The stopper
plate 421 receives an edge of the sheet pushed by a rotation of the
paddle 17. A moving arm 23 shown in FIG. 2 moves the stopper
21.
[0054] One edge of the stopper 21, as shown in FIG. 2, contacts a
first pulley shaft 10a, and the stopper 21 always protrudes by a
spring (not shown) to limit an edge of a sheet. Although, in FIG.
4, the stopper 21 is formed of a single plate, alternatively, as
shown in FIG. 5, the stopper 21 may be formed of a plurality of
stopper plates 221 disposed in the width direction of a sheet.
[0055] The saddle-stitching unit 30 has a staple-driving head unit
31 having a staple cartridge (not shown) and an anvil unit 32 for
bending the staple driven out of the staple-driving head unit 31.
The staple-driving head unit 31 and the anvil unit 32 are disposed
below and above a sheet bundle feed path 25 respectively and face
to each other. The saddle-stitching unit 30 is constructed as a
unit as shown by the dotted lines, and can be pulled out from the
sheet processing apparatus 2.
[0056] The staple-driving head unit 31 and the anvil unit 32 can
move on the sheet bundle feed path 25 disposed between the
staple-driving head unit 31 and the anvil unit 32 in a direction
perpendicular to a sheet transport direction (to right in FIG. 2).
The direction is also along a surface of a sheet bundle facing the
staple-driving head unit 31 and the anvil unit 32.
[0057] Guide rods 33 and 34 guide the staple-driving head unit 31
and the anvil unit 32, respectively, to move in the width direction
thereof. Screw shafts 35 and 36 shift the staple-driving head unit
31 and the anvil unit 32. A head drive shaft 38 drives the
staple-driving head unit 32 to drive staples, and an anvil drive
shaft 37 drives the anvil unit 31 to bend the staples,
respectively. The saddle-stitching unit 30 will be described in
detail later.
[0058] A head housing 224, as shown in FIG. 6, is provided in the
staple-driving head unit 31, and has a staple blade (not shown)
that drives the staples. The head housing 224 is attached to a
guide base block 208 that supports the head housing 224 and moves
in a width direction.
[0059] The guide base block 208 has a guide rod 34 inserted
therein. The guide rod 34 guides the staple-driving head unit 31
(head housing 224) to slide.
[0060] An attachment block 207 is provided on a side of the head
housing 224. The attachment block 207 is equipped with transmission
gears 230a and 230b and an arm 229 for driving the staple blade in
the head housing 224 by a force of the head drive shaft 38.
[0061] A pin 232 is disposed on the transmission gear 230b. The pin
232 moves along a cam face 231 of the arm 229. When the pin 232
moves, a recess portion at a tip of the arm 229 transports a pin
297 attached to a staple blade inside the head housing 224 along a
slit 227, thereby driving the staple blade to drive the
staples.
[0062] In the embodiment, as sown in FIG. 7, the attachment block
207 can be detached from the head housing 224 (and the guide base
block 208) in a direction shown by arrows A and B. In a usual
state, a positioning pin 299 of the head housing 224 engages a
recess 207a of the attachment block 207 for positioning and fixed
with a screw (not shown).
[0063] The guide base block 208 and the attachment block 207 have
the positioning sensors 280a and 280b placed thereon respectively.
These positioning sensors 280a and 280b which are detection means
can detect whether the attachment block 207 is attached to the
guide base block 208 and the head housing 224 or not and detect
whether the attachment block 207 is attached at a correct position
or not.
[0064] Such an arrangement allows only the attachment block 207 to
be removed upon clogging of the staple or similar troubles, thereby
increasing maintenance efficiency. The arrangement also allows the
head housing 224 having the staple driving staple blade to remain
in the apparatus together with the guide base block 208. This does
not deviate a precise relative position of the staple blade from an
anvil body 241 (FIG. 6) even with the action of attachment and
detachment upon maintenance, thereby preventing the staple from
stitching error in operation after maintenance and assuring a
secure saddle stitching.
[0065] Further, detection results of the positioning sensors 280a
and 280b are input to the control block 149 shown in FIG. 8. The
control block 149 inhibits the staple driving head unit 31 and the
anvil unit 32 from saddle stitching according to the detection
results of the positioning sensors 280a and 280b if the attachment
block 280 is not attached at all or has been attached in a position
that is incomplete. Such an operation can prevent staple stitching
error if a staple is clogged or not driven actually.
[0066] As for the saddle stitching inhibit control according to the
detection results of the positioning sensors 280a and 280b when the
attachment block 207 is mounted and removed as in FIG. 7, it may be
made possible by such a construction type that the head 224a having
the staple blade is integrated with the attachment block 207a as
shown in FIG. 9. For that construction, the detection results are
obtained by a positioning sensor 281a disposed on a guide base
block 208a and a positioning sensor 281b disposed on the attachment
block 207a.
[0067] As shown in the Figure, it also may be made possible by such
an alternative construction that an anvil unit 323 is made of a
guide base block 308 and a detachable attachment block 307. For
that construction, the detection results are obtained by a
positioning sensor 282a disposed on the guide base block 308 and a
positioning sensor 282b disposed on the attachment block 307. That
construction is the same as in FIG. 6.
[0068] Furthermore, according to this embodiment, it is controlled
to prohibit the saddle stitching based on the positioning detection
detected by the control block 149 on the sheet post-processing
apparatus when the attachment block 207 is mounted and dismounted.
However, it may also be made in an alternative way by using an
additional control means formed in the saddle stitching unit 30
itself. Still a further alternative method would be to have the
control unit 921 formed in the main body 1.
[0069] In addition, FIG. 10 illustrates that the saddle stitching
unit 30 has a gap detecting sensor 350 that can detect a space
between the staple driving head unit 31 and the anvil unit 32.
Further, the drive force of the drive shaft 38 is transmitted via a
timing belt 45 and via a staple/folding motor 170A located on the
anvil drive shaft 37 in the anvil unit 32 to a gear 175.
[0070] With the gear 175 rotated, the cam 173 located on the
rotating shaft 180 of the rotating shaft 175 on the gear 175 is
pressed to a fixed frame 111 on the anvil unit 32. As a result, a
movable frame 140 on the anvil unit 32 supported via a collar 37 on
the anvil drive shaft 37 to swing freely, as shown in FIG. 11,
resists against the urging force of the coiled spring 157 to
separate from the fixed frame 111 toward the staple driving head
unit 31.
[0071] The drive force of the head drive shaft 38 is transmitted to
the gear 230 via the gear 38A located on the head drive shaft 38 in
synchronization with the drive force of the head drive shaft 38
that moves the movable frame 140 of the anvil unit 32 via the
timing belt 45.
[0072] The gear 230, as shown in FIG. 10, has a cylindrical cam 232
having a notch 235 formed thereon. A detecting lever 366 having an
engaging portion 360 and a detecting end 362 provided thereon is
disposed to swing freely with a center of the shaft 363 being
pressed toward the cam 232 by a spring 364.
[0073] If the gear 230 is located at a position at which the gap
between the staple driving head unit 31 and the movable frame 140
of the anvil unit 32 is fully opened, as shown in FIG. 10, the
detecting lever 366 swings so that the engaging portion 360 can be
put into the cutout 235 of the cylindrical cam 232 by the spring
364.
[0074] With the engaging portion 360 put into the cutout 235 of the
cam 232, a detecting tip 365 of the detecting end 362 of the
detecting lever 366 is moved to a position at which the detecting
tip 365 is detected by the gap detecting sensor 350. As a result,
the gap detecting sensor 350 detects the detecting tip of the
detecting lever 366.
[0075] A signal from the gap detecting sensor 350, as shown in FIG.
9, is input to the control block 149. With the detection of the
detecting tip 365 by the gap detecting sensor 350, it is decided
that the space between the staple driving head unit 31 and the
movable frame 140 of the anvil unit 32 is fully opened as shown in
FIG. 10.
[0076] On the other hand, if the drive force of the head drive
shaft 38 moves the movable frame 140 on the anvil unit 32 via the
timing belt 45, as shown in FIG. 11, the gear 364 is rotated via
the gear 38A located on the head drive shaft 38 in synchronization
with the movement of the movable frame 140. The rotation force
resists the urging force of the spring 364 to push the engaging
portion 360 of the detecting lever 366 from the notch 235 to press
to the engaging surface of the circular cam 232. The engaging
portion 360 has a slant surface formed at the tip 360 thereof so
that the engaging portion 361 can be pressed up to the engaging
surface on the circular cam 232.
[0077] Thus, the detecting tip 365 of the detecting end 362 can not
be detected by the gap detecting sensor 350 while the engaging
portion 360 of the detecting lever detecting lever 366 is pressed
to the engaging surface of the circular cam 232. As the gap
detecting sensor 350 does not detect the detecting tip 365, the
control block 149 decides that the space between the staple driving
head unit 31 and the movable frame 140 of the anvil unit 32 is out
of a full open status as shown in FIG. 10.
[0078] It is described so far that the control block 149 decides
with the signal from the gap detecting sensor 350 whether or not
the space between the staple driving head unit 31 and the movable
frame 140 on the anvil unit 32 is fully open. Alternatively, a
detection range of the gap detecting sensor 350 can be made wider
to detect that the space between the staple driving head unit 31
and the movable frame 140 on the anvil unit 32 is made narrow from
the full open state to a desired range.
[0079] The both units 31 and 32 must be usually moved in the width
direction of the sheet bundle if saddle stitching is made at a
plurality of positions in the width direction of the sheet bundle
or if the staple driving head unit 31 and the anvil unit 32 are
moved to a staple replacement position to replace the staples. For
the saddle stitching unit 30 in this embodiment, however, the
control block 149 inhibits the both units 31 and 32 from moving
toward the width direction of the sheet bundle in the condition
that the gap detecting sensor 350 detects that the both units 31
and 32 have a space therebetween narrower than a predetermined
space (other than the full open status as in FIG. 10).
[0080] If the both units 31 and 32 are permitted to move in the
width direction of the sheet bundle in the narrow space state, the
sheet bundle positioned for saddle stitching at a loading portion
between the both units 31 and 32 may contact the staple driving
head unit 31 or the anvil unit 32 in a particular case, such as the
sheet bundle is floated up by curling or if the sheet bundle is
bulky due to too many number of sheets or too thick sheet
bundle.
[0081] Upon contact with the sheet bundle, the posture of the sheet
bundle that has been aligned once deforms. As a result, the sheet
bundle is stapled in the deformation state. Therefore, in this
embodiment, the posture of the sheet bundle could not be deformed
by any contact if the space is detected to exceed the predetermined
distance, that is, in the status shown in FIG. 10, the control
block 149 then permits the both units 31 and 32 to move in the
width direction of the sheet bundle.
[0082] However, as will be explained later, there could be a case
that a sheet presence detection sensor (not shown) detects that the
sheet bundle is not present in the space between the both units 31
and 32. The case occurs, as an example, if the sheet bundle does
not reach the space between the both units 31 and 32 in the status
that a preguide 370 for guiding the sheet bundle to a feed guide 39
is moved to a predetermined position and stands by, the preguide
370 being a supplement guide member for directing the sheet bundle
toward the feed guide 39 which is a guide member for guiding the
sheet bundle to the stitching position. This allows the staple
driving head unit 31 and the anvil unit 32 to return to a home
staple position that will be explained later.
[0083] The embodiment makes the above-described movement inhibit to
control in the width direction of the sheet bundle by way of
detecting the space between the both units 31 and 32 of the saddle
stitching unit 30. The way of control can be applied to any type of
a mechanism that a stapler having a head and an anvil mechanically
combined together other than the saddle stitching can be moved
along an edge of the sheet bundle to bind the edge at a plurality
of positions. If the space between the head and the anvil is
detected to be too narrow, the stapler may be inhibited from moving
along the edge of the sheet bundle.
[0084] In place of the control block 149 on the sheet
post-processing apparatus 2, alternatively, control means may be
established in the saddle stitching unit 30 itself so that the
control means can control to inhibit the both units 31 and 32 from
moving in the width direction of the sheet bundle according to the
gap detection between the both units 31 and 32. Still another
alternative is that the control unit 921 of the main body 1 may be
used to make the control for the image forming system.
[0085] The embodiment explained above has the anvil unit 32 moved
toward the staple driving head unit 31 thereby changing the gap.
Alternatively, the staple driving head unit 31 may be moved toward
the anvil unit 32. Still a further alternative could be that both
the units be moved toward each other.
[0086] It is alternatively possible to form a plurality of gap
detection sensors in a structure to automatically set to a
predetermined space by selecting a gap detection sensor to be used
by control means according to conditions such as the number of
sheets, the thickness of the paper of the sheet itself or the
humidity or other conditions. The fixed carrying guide 39 guides
the sheet stack carried inside the saddle stitching unit 30.
[0087] The folding unit 50 for the sheet bundle, on the other hand,
is the unit indicated by chain double-dashed line in FIG. 2 and can
be drawn out of the sheet post-processing apparatus 2 as in the
saddle stitching unit 30. The folding unit 50 has a bundle feed
guide 53, upper bundle feed roller 51, a lower bundle feed roller
52, a bundle detecting sensor 54 for detecting a leading edge of
the sheet bundle, an abutting plate 55 which is the pressing means,
the paired folding rollers 57a and 57b which are the paired
rotating bodies, and leading guide 56 provided therein.
[0088] A stack feed guide 53 guides the sheet bundle nipped and fed
between the upper feed roller 19 and the lower bundle feed roller
18 located at the inlet of the saddle stitching unit 30. The upper
stack feed roller 51 is located at the inlet of the folding unit
50. The lower bundle feed roller 52 is arranged to face the upper
bundle feed roller 51.
[0089] The upper bundle feed roller 51 is moved between a position
(solid line) at which the upper bundle feed roller 51 is pressed to
the lower bundle feed roller 52 and a separate position (dotted
line). The upper bundle feed roller 51 is moved from the position
separated from the lower bundle feed roller 52 to the contact
position with the lower bundle feed roller 52 to nip and feed the
sheet bundle together with the lower bundle feed roller 52 when the
leading edge of the sheet bundle passes between the upper bundle
feed roller 51 and the lower bundle feed roller 52 by the upper
feed roller 19 and the lower feed roller 18 positioned at the inlet
on the saddle stitching unit 30. 71A stack detecting sensor 54 for
detecting the leading edge of the sheet bundle presses the upper
stack feed roller 51 against the lower bundle feed roller 52 when
detecting the leading edge of the sheet bundle. The stack detecting
sensor 54 is also used to set and control the folding position in
the feed direction of the sheet bundle. The paired folding rollers
57a and 57b are cylindrical rollers having flat parts extending in
a width direction thereof. Both the rollers are urged in the
directions to press each other when rotated.
[0090] The abutting plate 55 is made of a stainless steel plate of
around 0.25 mm thick at an edge thereof. The abutting plate 55 is
positioned right above the paired folding rollers 57a and 57b, and
a leading edge thereof can be moved close to the nips of the paired
folding rollers 57a and 57b.
[0091] Around the upper portion of the paired folding rollers 57a
and 57b, there are formed ark-like backup guides 59a and 59b to
guide and feed the sheet bundle together with the stack feed guide
53. The backup guides 59a and 59b are interconnected to move with
the abutting plate 55 moving up and down to make an opening around
the sheet bundle for the paired folding rollers 57a and 57b when
the leading edge of the abutting plate 55 moves close to the nips
of the paired folding rollers 57a and 57b.
[0092] The leading guide 56 guides downward the sheet bundle nipped
and fed by the upper stack feed roller 51 and the lower bundle feed
roller 52 until the leading edge (the downstream edge) of the sheet
bundle sags downward at a sheet bundle path 58. In the stack
delivery rollers 60a and 60b, the roller 60a is a drive roller, and
the roller 60b is a driven roller.
[0093] A sheet bundle stacking tray 80 for the folded sheet
bundles, as shown in the Figure, can stack sheet bundles that have
been folded by the paired folding rollers 57a and 57b and
discharged out by the paired bundle discharge rollers 60a and 60b.
The sheet bundle discharged inside the sheet bundle stacking tray
80 is pressed by the folded sheet holder 81 urged downward by a
spring or its own weight.
[0094] In turn, the following describes the construction of the
processing tray 8 and the saddle stitching unit 30 of the sheet
processing apparatus 2 in detail.
[0095] First, the processing tray 8 is described below. The
processing tray 8, as shown in FIG. 3, has a first pulley 10 and a
second pulley 11 disposed virtually at a center thereof. The first
pulley 10 and the second pulley 11 have a transfer belt 12 trained
therebetween. On the first pulley shaft 10a, lower bundle feed
rollers 18 are formed in two locations on each side of the sheet
and substantially at the center of the sheet in the width direction
thereof, the lower bundle feed rollers 18 being tire-like hollow
rollers.
[0096] The first pulleys 10 are driven to rotate by the
counterclockwise rotation of the first pulley shaft 10a in FIG. 2
with a one-way clutch 75 interposed between the first pulleys 10
and the first pulley shaft 10a, and made for free driving to stop
by clockwise rotation of the first pulley shaft 10a. The first
pulley shaft 10a is interconnected via the pulley 73 fixed to the
first pulley shaft 10a, the timing belt 74, and gear pulleys 72 and
71 to the motor shaft 70a on the stepping motor 70 which serves as
a source for the feed drive.
[0097] Therefore, the lower bundle feed roller 18 fixed to the
first pulley shaft 10a is driven to rotate when the stepping motor
70 rotates to move the sheet on the processing tray 8 toward the
staples in FIG. 2 (in the direction of the arrow B in FIGS. 2 and
3). The feed belt 12, however, is stopped because no drive force is
transmitted thereto because of the one-way clutch 75. If the
stepping motor 70 rotates to move the sheet toward the sheet
elevator tray 90, the lower bundle feed roller 18 and the feed belt
12 rotate toward the sheet elevator tray 90 (in direction of arrow
A in FIGS. 2 and 3).
[0098] The transfer belt 12, as shown in FIG. 12, has a pushing
pawl 13 disposed thereon. The processing tray 8 has a pushing pawl
sensor 76 and a pushing pawl detecting arm 77 disposed thereunder
to determine a home position thereof for the pushing pawl 13. In
this embodiment, the home position (HP) is determined at the
position where the pushing pawl sensor 76 is turned from OFF to ON
as the pushing pawl detecting arm 77 is pressed by the pushing pawl
13 moved together with the feed belt 12.
[0099] In the Figure, let P denote a nip for the lower bundle feed
roller 18 and the upper feed roller 19, L1 a length from the nip P
to the stopper 21, and L2 a length from the nip P to the pushing
pawl 13 along the feed belt 12. L1 and L2 are set as L1<L2.
[0100] In turn, the following describes the sheet feed operation of
the processing tray 8 explained above in construction. To feed the
sheet bundle to the elevator tray 90, first, a cam or the like (not
shown) moves the upper feed roller 19 below the lower feed roller
19 to nip the sheet bundle together with the lower feed roller 19.
Second, the stepping motor 70 (FIG. 3) is rotated to rotate the
first pulley shaft 10a counterclockwise. The lower feed roller 19
then is rotated to move the sheet bundle toward the elevator tray
90 in the arrow A direction.
[0101] Note that also that the upper feed roller 19 is rotated by
the stepping motor 70. Therefore, the sheet bundle is moved in the
direction of the arrow A from the position of the stopper 21 inside
the saddle stitching unit 30, by the rotation of the lower bundle
feed roller 18 and the upper feed roller 19. When the sheet bundle
passes the nip position P, the pushing pawl 13 hits with rotation
of the feed belt 12. With the pushing pawl 13, the sheet bundle is
fed to the elevator tray 13 while being pressed in the direction of
the arrow A.
[0102] Because of L1<L2 in the length relationship mentioned
above, the pushing pawl 13 presses the bottom of the sheet bundle
upward (from the right side in FIG. 12), thereby always pressing
the edge of the sheet bundle in an upright status. This does not
cause excess stress in the transferring of the sheet bundle.
[0103] To feed the sheet bundle toward the saddle stitching unit 30
for saddle stitching, on the other hand, the pushing pawl 13 move
counterclockwise from the HP position (FIG. 12) before receiving
the sheet bundle moved from the stopper 21 by the paired rollers 18
and 19 synchronized therewith to feed the sheet bundle and push it
out.
[0104] However, if the sheets fed into the processing tray 8 are
not saddle-stitched by the saddle stitching unit 30, the sheet
bundle does not need to move to feed the sheet bundle to the
stopper 21 position. The stepping motor 70 is driven in advance to
move the pushing pawl 13 from the HP position in FIG. 12 to a
movement idle position (Pre-HP position) by a predetermined
distance .alpha. from the nipping position of the lower bundle feed
roller 18 and the upper feed roller 19 in a direction toward the
elevator tray 90.
[0105] The distance (L2+.alpha.) from the HP position to the Pre-HP
position can be set by changing a step number count of the stepping
motor 70. If the present sheet processing apparatus 2 needs no
saddle stitching for sheets, therefore, the sheets may not be
transferred to the stopper 21, but the pushing pawl 13 can be moved
to the Pre-HP position in advance to stack the sheets on the
elevation tray 90 before pushing the sheet stack out. This means
that the sheet post-processing apparatus 2 is available for a
high-speed duplicating machine.
[0106] Note that if the Pre-HP position of the pushing pawl 13 is a
position where the feed guide 7 and the top of the pushing pawl 13
overlap each other, as shown in the Figure, the sheets fed one by
one can be securely stacked at the Pre-HP position where the
pushing pawl 13 exists. Such an arrangement allows the pushing pawl
13 to deliver the sheet bundle to the elevator tray 90 quickly.
[0107] In turn, the following describes the saddle stitching unit
30. The saddle stitching unit 30, as shown in FIG. 13, has right
and left unit frames 40 and 41, guide rods 33 and 34, screw shafts
35 and 36, and drive shafts 37 and 38 situated between the frames
40 and 41, the anvil unit 32 thereabout and the staple driving head
unit 31 thereunder.
[0108] The screw shaft 36 is engaged with the staple driving head
unit 31. The staple driving head unit 31 is moved in the horizontal
direction in the Figure by rotation of the screw shaft 36. The
anvil unit 32 also is arranged similarly.
[0109] The screw shaft 36 is connected with the stapler slide motor
42, which is the moving means, via the gear 36A outside the unit
frame 41. Drive force of the stapler slide motor 42 is transmitted
also to the anvil unit 32 by a timing belt 43. This allows the
staple driving head unit 31 and the anvil unit 32 to move in a
direction (horizontal direction in FIG. 13) without deviation of
vertical positions thereof.
[0110] The stapler slide motor 42, therefore, can be driven to
control the staple driving head unit 31 and the anvil unit 32 to
move to a desired position depending on the width of the sheet,
thereby allowing the staples to be driven at desired positions.
[0111] Top guides 46a, 46b, 46c, and 46d, which are float
preventing guide members, are movably supported on the guide rod 33
and the anvil drive shaft 37 above the sheet bundle feed path 25
(FIG. 2) in an area surrounded by the anvil unit 32 and the right
and left unit frames 40 and 41 as shown in FIG. 14. A roller 381
and the preguide 370 are disposed on the head-unit 31.
[0112] Compression springs 47a, 47b, 47c, 47d, 47e, and 47f of an
elastic material are interposed between the unit frame 41 and the
upper guide 46a, between the upper guide 46a and the upper guide
46b, between the upper guide 46b and the anvil unit 32, between the
anvil unit 32 and the upper guide 46c, between the upper guide 46c
and the upper guide 46d, and between the upper guide 46d and the
unit frame 41, respectively. The top guides 46a, 46b, 46c, and 46d
move the upper guide rod 33 and the anvil drive shaft 37 in
coordination with the movement of the anvil unit 32.
[0113] As an example, if the sheet bundle is saddle stitched on a
right side thereof, as shown in FIG. 15, the staple driving head
unit 31 and the anvil unit 32 move to desired stitching positions
on the right side from the position shown in FIG. 14 while keeping
a relative positional relationship therebetween. Along with the
movement, the compression springs 47d, 47e, and 47f on the right
side are compressed by the anvil unit 32 in coordination with the
movement of the anvil unit 32. The top guides 46c and 46d are moved
to the right side as pushed by the compression springs 47d and
47e.
[0114] The compression springs 47a, 47b, and 47c placed to the left
side of the anvil unit 32, on the other hand, are extended in
coordination with the movement of the anvil unit 32. The top guides
46a and 46b also move to the right side to serve for guiding at
desired positions depending on sheet stitching positions.
[0115] The drive forces for moving the head to drive the staples in
the staple driving head unit 31, to move the staples, and to bend
the staples in the anvil unit 32 are provided through the coupling
device 44 from the sheet processing apparatus 2 and are also
transmitted to the anvil unit 32 through the timing belt 45 on the
unit frame 40.
[0116] FIG. 16 shows parts of a side of the saddle stitching unit
30. The stopper 21 is connected with the moving arm 23 by the
connecting pin 23c, the connecting lever 22, and the connecting pin
21a. The stopper 21 is pivoted by the first pulley shaft 10a.
[0117] The following describes the appearance and disappearance of
the stopper 21 in the sheet bundle feed path 25 to set the staple
driving positions on the edge of the sheet bundle with the staple
driving head unit 31 moved in the width direction of the sheets, in
reference to FIGS. 13 and 16.
[0118] Below the head unit 31, as shown in FIG. 13, the stopper
abutting protrusion 24 is disposed to engage the stopper 21 with
the moving arm 23. The movement of the head unit 21 causes the
stopper abutting protrusion 24 to abut against the moving arm
protrusion 23b, which in turn causes the moving arm 23 to rotate
around the turning shaft 23a in the counter-clockwise direction
moving to the position of the dotted lines, as can be seen in FIG.
16. With the movement, the stopper 21, therefore, can not prevent
the staple driving head unit 31 and the anvil unit 32 from moving
in the width direction of the sheet bundle.
[0119] In the above-mentioned operational construction that the
movement of the staple driving head unit 31 makes the stopper
engaging projection 24 engage the moving arm projection 23b, a
plurality of stoppers 221 forming the stopper 21 as shown in FIG.
5, may be alternatively placed in position and can all be saved
from the staple path and the feed path 25.
[0120] In turn, the following describes the control operation of
the sheet processing apparatus 2 with reference to FIG. 8. A
control block 149 comprises a central processing unit (CPU), a ROM
for storing control means in advance that the CPU executes, and RAM
for storing the operational data of the CPU and control data
received from the main body 1 of the copier 20. The control block
149 has I/O devices formed therein.
[0121] A block for aligning the sheets has a front aligning HP
sensor 151 and a rear aligning HP sensor 152 for setting a home
position (HP) of the aligning plates 9 that can align both edges of
the sheets in the processing tray 8. The aligning plates 9 (FIG. 3)
stand by at positions of the front aligning HP sensor 151 and the
rear aligning HP sensor 152 until the first sheet is fed into the
processing tray 8.
[0122] A front aligning motor 14 is a pulse motor for moving the
front aligning plate 9, and a rear aligning motor 14 is a pulse
motor for moving the rear aligning plate 9. The aligning motors 14
move the respective aligning plates 9 to align the width of the
sheet bundle according to the width thereof. The aligning plates 9
can freely deviate each sheet bundle in the width direction.
[0123] A circuit for the elevator tray comprises a paper sensor 93
for detecting a top surface of the sheets thereon, an elevation
clock sensor 150 for detecting the number of rotations of an
elevator tray motor 155 with an encoder, and an upper limit switch
153 and a lower limit switch 154 to limit an elevation range for
the elevator tray 90. Signals input from the paper sensor 93 and
elevation clock sensor 150 and the upper limit switch 153 and the
lower limit switch 154 control the elevator tray motor 155 to drive
the elevator tray 90.
[0124] A block (relative to the sheet detection) for detecting
whether or not a sheet or sheet bundle is stacked on the elevator
tray 90 and in the sheet bundle stacking tray 80, is equipped with
an elevator tray paper sensor 156 for detecting the presence on the
elevator tray 90 and a sheet bundle stacking paper sensor 157 in
the sheet bundle stacking tray 80. Those sensors 156 and 157 are
also used as sensors for issuing alarms to an operator if any sheet
remains before the sheet post-processing apparatus 2 is started or
if a sheet bundle is not removed after a predetermined time
elapses.
[0125] The block relative to a door open-close detection for
detecting the opening of a door of the sheet processing apparatus 2
and whether or not the main body 1 of the copier 20 is properly
mounted on the sheet processing apparatus 2 has a front door sensor
158 and a joint switch 159 for detecting whether or not the main
body 1 of the image forming apparatus 20 has the sheet processing
apparatus 2 mounted correctly.
[0126] The block (relative to sheet feed and bundle feed) for the
sheet feed operation and the sheet bundle feed operation with the
stacked sheets comprises a sheet detecting sensor 4 for detecting
on the feed guide 3 that a sheet is fed from the main body 1 of the
copier 20 to the sheet post-processing apparatus 2, a processing
tray sheet detecting sensor 160 for detecting the presence of a
sheet on the processing tray 8, a center stitching position sensor
95, a center stitching and folding position sensor 95' for
detecting the leading edge of the sheet bundle in the feed
direction to deduce the same position for folding the sheets as the
staple driven position, a pushing pawl sensor 76 for detecting a
home position of the pushing pawl 13 established on the feed belt
12 for transferring the sheet bundle on the processing tray 8
toward the elevator tray 90, and an upper stack feed roller HP
sensor 161 for detecting the home position at which the upper stack
feed roller 51 at an inlet of the folding unit 50 is separated away
from the lower bundle feed roller 52. The circuit can control the
feed motor 162 and the stepping motor 70 according to signals from
the respective sensors.
[0127] The rotating force of the feed motor 162 is transmitted to
the paired feed rollers 5, the paired discharge rollers 6, the
upper stack feed roller 51, the lower bundle feed roller 52, and
the paired stack discharge rollers 60a and 60b. The reverse
rotation of the feed motor 162 turns the upper roller moving cam 68
to move the paired stack feed rollers 51. The rotating force of the
stepping motor 70 is transmitted to the lower bundle feed roller 18
and the upper feed roller 19 formed on the processing tray 8 and
the first pulley 10 to circulate the feed belt 12.
[0128] The block (relative to paddle) for controlling the paddle 17
comprises a paddle HP sensor 163 to detect the rotating position of
the paddle 17 and an upper feed HP sensor 164 to detect the
position where the upper feed roller 19 separates from the lower
bundle feed roller 18, thereby controlling the paddle motor 165
according to signals from the sensors 163 and 164.
[0129] The block (relative to staple/folding) for controlling the
staple/folding operation is comprised of a staple HP sensor 166 to
detect that the staple driving head unit 31 and the anvil unit 32
in the saddle stitching unit 30 can drive staples, a staple sensor
167 to detect whether or not the staple driving head unit 31 has
staples set therein, a staple slide HP sensor 168 to detect whether
or not the sheet bundle is at a home position (FIG. 13) when
start-moving in the sheet feed direction between the both units 31
and 32, a staple/folding clock sensor 171 to detect the rotation
direction of the staple/folding motor 170 that can switch the drive
of the saddle stitching unit 30 and the folding unit 50 to normal
or reverse, and a safety switch 172 for detecting that the saddle
stitching unit 30 and the folding unit 50 are operable. The circuit
having the sensors and switches mentioned above controls the
stapler slide motor 42 and the staple/folding motor 170.
[0130] The stapler slide motor 42 transmits the rotating force to
the screw shaft 36 to move the staple driving head unit 31 and the
anvil unit 32 in the width direction thereof. A gear 170 is
arranged to drive the coupling device 44 (FIG. 14) for the saddle
stitching unit 30 in one of the normal or reverse rotation
direction or the coupling device 137 (FIG. 6) for the folding unit
50 in the other rotation direction.
[0131] Next, the following describes operations in the process
modes of the sheet processing apparatus 2. This embodiment of the
sheet processing apparatus 2 provides the following basic
modes.
[0132] Non-staple mode: A mode for stacking the sheets onto the
elevator tray 90 without stitching;
[0133] Side staple mode: A mode for saddle stitching the sheets at
one or a plurality of positions on an edge (side) thereof in the
sheet feed direction before loading the sheets onto the elevation
tray 90;
[0134] Saddle staple mode: A mode for stitching the sheets at a
plurality of positions on a half length of the sheets in the sheet
feed direction and for folding and binding the sheets at the
stitched positions before stacking the sheets onto the sheet bundle
stacking tray 80.
[0135] At first, non-staple mode is explained. With this mode of
process selected, the control block 149 drives the stepping motor
70 for rotating the transfer belt 12 to move the pushing pawl 13 at
the home position (HP in FIG. 12) to the pre-home position (Pre-HP
in FIG. 12) that is a sheet loading reference position on the
processing tray 8 before stopping.
[0136] At the same time, the control block 149 drives the carrying
motor 162 to rotate the pair of carrying rollers 5 and the pair of
delivery rollers 6 and waits for a sheet to be delivered from the
delivery rollers 1a and 1b of the main body 1 of the duplicating
machine 20. After that, when the sheet is discharged, the paired
feed rollers 5 and the paired discharge rollers 6 feed the sheet to
the processing tray 8. Then, when the sheet detecting sensor 4
detects the sheet, start timings of the aligning motors 14 for the
aligning plates 9 and the paddle motor 165 for rotating the paddle
17 are measured.
[0137] The control block 149 drives the aligning motors 14 and the
paddle motor 165 while the sheet is discharged and stacked onto the
processing tray 8. With the drive, the aligning plates 9 move in
the width direction traversing the sheet feed direction to align
the both edges of the sheet, and the paddle 17 is rotated to make
one side of the edges of the sheets strike the pushing pawl 13 at
the Pre-HP position to align the sheets. This operation is repeated
whenever the sheet is discharged to the processing tray 8.
[0138] After that, if a predetermined number of sheets is aligned
to the pushing pawl 13, the control block 149 stops the feed motor
162 and the paddle motor 165 from rotating, and also restarts the
stepping motor 70 for driving the feed belt 12. With this
operation, the sheet bundle is moved to the elevator tray 90 (the
arrow A direction in FIG. 3) before being loaded on the elevator
tray 90.
[0139] Along with the delivery of the sheet bundle, the control
block 149 makes the elevator tray motor 155 move down to a certain
distance in a downward direction of the elevator tray 90 once.
Subsequently, it drives the elevator tray motor 155 upward until
the paper sensor 93 detects the top sheet before stopping, and
makes the elevator tray motor 155 idle until the following sheet
bundle is loaded thereupon.
[0140] In turn, the side staple mode is described below. When the
side staple mode is selected, the control block 149 drives the feed
motor 162 to rotate the paired feed rollers 5 and the paired
discharge rollers 6 to deliver a sheet from the main body 1 of the
copier 20 to the processing tray 8 to stack. The control block 149
also drives the aligning motors 14 and the paddle motor 165 while
the sheet is discharged and stacked. With this operation, the sheet
is aligned on both edges in the width direction thereof by the
aligning plates 9, and the leading edge of the sheet is transferred
to the stopper 21 to stop. This operation is repeated for a
specified number of sheets.
[0141] In the state where the sheet bundle is restricted by the
stopper 21, the upper feed roller 19 is moved to the lower bundle
feed roller 18 to make the upper feed roller 19 and the lower
bundle feed roller 18 nip the sheet bundle. At that time, the
staple driving head unit 31 and the anvil unit 32 are both
positioned at the staple home position shown in FIG. 13.
[0142] The staple home position is a position where one stitching
is made on the left unit frame 41 side shown in FIG. 13, that is,
on the back side of the duplicating machine 20 and the sheet
post-processing apparatus 2 shown in FIG. 1. Positioning the both
units 31 and 32 for the staple home position is made by moving the
both units 31 and 32 for a distance of a specific number of pulses
from the HP sensor (not shown) disposed on the left unit frame 41
side shown in FIG. 13.
[0143] If the one-position stitching is specified, for example, the
control block 149 makes the staple/folding motor 170 to be driven
to rotate in the staple moving direction to make the both units 31
and 32 proceed with stitching. To stitch the sheets at a plurality
of positions on the edge thereof, the stapler slide motor 42 should
be driven to move the both units 31 and 32 from the staple home
position to a desired staple position before proceeding with
stitching.
[0144] After the stitching process is finished, the lower feed
roller 18 and the upper feed roller 19 are rotated, and the
transfer belt 12 is moved toward the elevation tray 90 side (arrow
A direction in FIG. 3) by the stepping motor 70. This delivers the
sheet bundle to the lower bundle feed roller 18, the upper feed
roller 19, and pushing pawl 13 in this order before loading the
sheet bundle onto the elevator tray 90. The operation of the
elevator tray 90 is the same as in the nonstaple mode described
above, so that an explanation shall be omitted.
[0145] In turn, the saddle staple mode is described below. Because
the stacking of the sheets discharged from the copier 1 onto the
processing tray 8 is similar to that of the side staple mode of
operation described above, a description shall be omitted.
[0146] After the sheets are aligned and loaded on the processing
tray 8, the upper carrying roller 19 is moved down to the lower
carrying roller 18 side to make the upper carrying roller 19 and
the lower carrying roller 18 nip the sheet stack. In turn, the
stopper 21 is retracted away from the feed path 25 before the
control block 149 drives the stapler slide motor 42 to transfer the
sheet bundle in the arrow B direction in FIG. 3.
[0147] The drive allows the stopper engaging projection 24 on the
staple driving head unit 31 also to move as shown in FIG. 13 to
engage the moving arm 23. This retracts the stopper 21 from an area
where the staple driving head unit 31 and the anvil unit 32 move,
as shown in FIG. 16.
[0148] It should be noticed that the stopper 21 may be
alternatively replaced by a single wide stopper plate 421 (FIG. 4)
or a plurality of stopper plates 221 (FIG. 5) extending in the
direction in which the staple driving head unit 31 moves along the
guide rod 34, the direction being a direction orthogonal to the
direction in which the sheets are delivered from the duplicating
machine 20 to the sheet post-processing apparatus 2 or a direction
orthogonal to the direction in which the sheet bundle is fed in the
sheet bundle feed path.
[0149] By the engagement of the stopper engaging projection 24 of
the staple driving head unit 31 with the moving arm 23, all the
stopper plates are moved away from the moving area of the staple
driving head unit 31 and the anvil unit 32 to make the sheet bundle
feed path free.
[0150] In this embodiment, the stopper engaging projection 24 is
disposed in the staple driving head unit 31. Alternatively, the
stopper engaging projection 24 can be placed in the anvil unit 32
SO as to retract the stopper away from the moving area of the
staple driving head unit 31 and the anvil unit 32 along with
movement of the anvil unit 32 to make the sheet bundle feed path
free.
[0151] In such a construction, the staple driving head unit 31 and
the anvil unit 32 move from the home staple position shown in FIG.
13 along the guide rods 33 and 34 to open the sheet bundle feed
path 25 free before stopping at the driving set positions in the
width direction. The stopping positions of the both units 31 and
32, however, can be specifically controlled to change depending on
the difference of the alignment reference by the aligning plate 9
and difference of the sheet size as will be described later.
[0152] Further, the control block 149 rotates the stepping motor 70
in a direction reverse to the non-staple and side staple modes in
the process. This drive makes the sheet bundle feed in the
direction reverse (the direction of the arrow B in FIGS. 2 and 3)
to the elevator tray 90. If, in the transfer, the stack detecting
sensor 54 in the folding unit 50 detects a leading end of the sheet
stack in the carrying direction (sheet size data), the upper
carrying roller 19 and the lower carrying roller 18 carry and stop
the sheet stack to a position at which the approximate middle
position in the sheet carrying direction coincides with the
stitching position according to the sheet length information in the
carrying direction sent in advance.
[0153] It should be noticed that if the stepping motor 70 rotates
in the reverse direction, the one-way clutch 75 interposed between
the first pulley 10 and the first pulley shaft 10a for tightly
stretching the transfer belt 12 prevents the rotating force of the
stepping motor 70 from transmitting but keeps the transfer belt 12
and the pushing pawl 13 stopped at the home position.
[0154] Next, the control block 149 rotates the staple/folding motor
170 for driving the drive shaft 38 and the anvil drive shaft 37 to
rotate in the directions for operation thereof to stitch. When
there requires a plurality of stitchings at a plurality of
positions, the stapler slide motor 42 is driven to rotate the screw
shafts 35 and 36 to move to the specific positions in the width
direction before stitching.
[0155] After saddle stitching the sheet bundle at a single position
or a plurality of positions, the both units 31 and 32 are moved
from the final stitching position to the home staple position shown
in FIG. 13 along the guide rods 33 and 34. This disengages the
stopper engaging projection 24 of the staple driving head unit 31
from the moving arm 23. As a result, the stopper 21 (stopper plate
421 or 221) returns to the moving area of the both units 31 and 32,
closes the feed path 25, and prepares for the alignment of the
leading edge of the next sheets.
[0156] Accordingly, in a stroke of the both units 31 and 32 moving
from the staple home position to the staple position and returning
again to the staple home position, the position for retracting the
stopper 21, the position for stitching process, and the position
for returning the stopper in the sheet bundle feed path 25 are
already set. In the stroke, there is also set the position for a
preguide 370 (which will be described later) to guide the sheet
bundle.
[0157] It should be noticed that timing when the both units 31 and
32 move from the position for stitching the final sheet bundle to
the position for allowing the stopper 21 to return to the feed path
25 do not need to wait until the sheet bundle having the finished
stitching is entirely delivered from the sheet post-processing
apparatus 2. If a trailing edge of the sheet bundle S in the feed
direction has passed over the stopper 21 as shown in FIG. 27, for
example, the stopper 21 can be moved to the position for returning
into the feed path 25.
[0158] Therefore, alternatively, the both units 31 and 32 may start
to move at an instance when the both units 31 and 32 reach a
position to which the stopper 21 is returned after the trailing
edge of the sheet bundle has passed over the stopper 21 with
reference to the size of the sheet, a sheet bundle feed speed, and
other factors. Such a scheme can make it fast to make ready for
accepting a next sheet stack.
[0159] The leading edge of the sheet bundle may be caught at an
upstream edge of the feed guide disposed in a lower casing 30A
having the staple driving head unit 31 of the saddle stitching unit
30 shown in FIG. 28 attached thereto when the sheet bundle passes
over the stopper 21 moved to the retracted position to the
stitching position. This causes the sheet bundle to be deformed in
posture and the sheets to be stacked, resulting in incorrect saddle
stitching.
[0160] To prevent such a failure, in the embodiment, the preguide
370 is provided at an upstream side of the feed guide. The preguide
370 guides the sheet bundle to the feed guide 39 without allowing
the leading edge thereof to touch the upstream edge of the feed
guide 39 when the sheet bundle is fed to the stitching
position.
[0161] The preguide 370, as shown in FIG. 28, is disposed to
project higher than the feed guide 39 to prevent the leading edge
of the sheet bundle from being caught by the upstream of the feed
guide 39. Also, the preguide 370 has a slope 370a provided for
guiding the sheet bundle above the feed guide in the projection
direction to prevent the leading edge of the sheet bundle from
touching the upstream edge of the feed guide 39 after the preguide
370 abuts against the sheet bundle.
[0162] With a preguide 370, the sheet bundles can be guided to the
feed guide 39 without the leading edges thereof catching on an
upstream side of the feed guide 39. The sheet bundles led to the
feed guide 39 can be firmly supported in the width direction by the
feed guide 39. The sheet bundles can be correctly saddle stitched
by the staple-driving head unit 31 and the anvil unit 32.
[0163] According to the preferred embodiment of the present
invention, the preguide 370 is disposed to one side of the feed
guide 39 in the upstream direction of sheet transport via the
turning shaft 370b, as can be seen in FIGS. 19(a) to (c). When the
staple-driving unit 31 moves in a width direction of the sheets,
the preguide 370 is pressed by the staple-driving unit 31 and
rotates around the turning shaft 370b. As a result, the preguide
370 retracts to a position where it does not interfere a movement
of the staple-driving unit 31.
[0164] Also, the preguide 370 is urged by a spring (not shown) in
the protruding direction to guide the sheet bundle above the feed
guide 39, so that the leading edge of the sheet bundle does not
touch a upstream edge of the feed guide 39. The preguide 370
protrudes above the feed guide 39 when not being pressed by the
staple-driving unit 31.
[0165] According to the preferred embodiment of the present
invention, an inclined contact portion 370c is attached to the
preguide 370. The staple-driving unit 31 presses the inclined
contact portion 370c when the staple-driving unit 31 moves in a
sheet width direction, and the preguide 370 can smoothly move
(rotate) to the retracted position.
[0166] Also, two pairs of rollers 381 are disposed on the cover 380
of the staple-driving unit 31 at a position facing the preguide 370
(see FIG. 18). The rollers 381 touch the contact portion 370c to
assist the retracting movement of the preguide 370 when the
staple-driving head moves.
[0167] As can be seen in FIG. 19(a), the staple-driving unit 31
moves in the direction of the arrow A. Then, when the
staple-driving unit 31 presses against the contact portion 370c
with the roller 381, the preguide 370 rotates around the turning
shaft 370b in the direction of the arrow B as can be seen in FIG.
19(b), thereby being moved to the retract position, as can be seen
in FIG. 19(c).
[0168] Through the rotational movement of the preguide 370 to the
retracted position by the staple-driving unit 31, the
staple-driving head 31 can be moved without being hindered by the
preguide 370, thereby securing a wide space for stitching of the
staple-driving unit 31. Also, the staple-driving unit can be moved
to a side direction for easier access to replace staples.
[0169] In the embodiment, the preguide 370 is disposed to the feed
guide 39 to move separately, but it is also acceptable to dispose
the preguide 370 to the staple-driving head unit 31 so that the
preguide 370 can move together with the staple-driving head unit
31.
[0170] In the case that the preguide 370 is disposed to the
staple-driving head unit 31, when the sheet bundle aligned by the
aligning plates 9 with reference to a center in the width direction
is transported to the feed guide 39, the preguide 370 moves to a
center in the width direction along with the staple-driving unit
31, or its proximity, for example, to a stitching position. This
allows the sheet bundle to be balanced and guided to the feed guide
39.
[0171] In case, the sheet bundle, which is aligned on the base of
either side of the edges in the width direction by the aligning
plate 9, is transferred to the feed guide 39, the center of the
sheet changes depending of the sheet size. However, the control
block 149 as control means can control the stapler slide motor 42
on the basis of at least one of the aligning reference and the
sheet size data, so that the preguide 370 is moved to the center
position in the width direction or to the position close thereto
depending on size of the sheet together with the staple driving
head unit 31. With such a control, the sheet bundle can be guided
into the feed guide 39 in good balance.
[0172] As the preguide 370 is disposed to the staple-driving unit
31, the preguide 370, moving together with the staple-driving unit
31, touches the side plate 382 on the lower case 30A (see FIG. 18)
when the staple-driving unit 31 moves close to the side of the feed
guide 39 to staple the sheet bundle, thereafter moving to the
retracting position along the side plate 382.
[0173] Since the preguide 370 moves to the retracting position, the
staple-driving unit 31 is able to move freely without the hindrance
of the preguide 370. Note that by disposing the roller 381 to the
side plate 382 on the lower case 30A, as shown in the FIGS. 19(a)
to (c), the preguide 370 is able to move securely to the retracting
position.
[0174] In the embodiment, the preguide 370 is disposed on the
staple driving head unit 31 side viewed from the sheet bundle since
a leading edge of the sheet bundle curled on the side of the staple
driving head unit 31 arranged on a printing side of the sheets
tends to be caught by the upstream edge of the feed guide 39 as
curling occurs usually on the leading edge of the sheets.
[0175] The invention is not limited to the embodiment mentioned
above, and alternatively the feed guide may be attached to the
anvil unit 32. If the feed guide may be attached to the anvil unit
32, the preguide 370 may be placed on the side of the anvil unit 32
as viewed from the sheet bundle, for example, on an additional side
cover (not shown) fixed to the anvil unit 32.
[0176] It should be noted that the feed guide 39 has a cutout
portion 390 that is slanted on the upstream edge thereof from the
center portion toward the edge in the sheet feed direction as shown
in FIG. 18. With the slanted cutout portion 390, the edges of the
sheet bundle can be smoothly guided to a guide surface on the feed
guide 39.
[0177] When the sheet bundle has been fed to the stitching
position, the leading edge of the sheet bundle in the feed
direction already passes an area between the lower bundle feed
roller 52 in the folding unit 50 and the upper stack feed roller 51
separated from the lower bundle feed roller 52.
[0178] After the stitching is completed, the sheet bundle is fed to
come to an approximate center in the feed direction, that is, to
bring the stitched position to become the folding position. The
staple/folding motor 170 then is driven in a reverse direction of
the stitching process. The pair of folding rollers 57a and 57b is
rotated in the directions of nipping the sheet bundle S, and the
abutting plate 55 is moved down as shown in FIG. 22. At the same
time, the backup guides 59a and 59b move to free the paired folding
rollers circumferences at the sheet bundle side.
[0179] After the abutting plate 55 has moved the rotating paired
folding rollers 57a and 57b having the sheet bundle nipped
therebetween, the sheet bundle S is rolled in between the paired
folding rollers 57a and 57b. After that, while the abutting plate
55 moves in the direction separating from the sheet bundle, the
sheet bundle is further folded by the paired folding rollers 57a
and 57b.
[0180] At this point, the bundle feed upper roller 51, bundle feed
lower roller 52 and the paired bundle feed rollers 60a and 60b are
rotated in the direction to discharge the sheet bundle to the stack
loading tray by the feed motor 162. The paired folding rollers 57a
and 57b, on the other hand, are stopped when the abutting plate 55
moves up and is detected by the abutting plate HP sensor (not
shown).
[0181] The sheet bundle S nipped and fed by the paired stack
discharge rollers 60a and 60b is discharged to and stacked on the
sheet bundle stacking tray 80. The folded sheet bundle is held down
by the folded sheet holder 81 so that it does not open, thereby not
preventing a subsequent folded sheet bundle from being fed in.
[0182] It should be noted that the upper stack feed roller 51
separates from the lower bundle feed roller 52, moves up, and
prepares to feed in the next sheet bundle when a period of time
available for the paired stack discharge rollers 60a and 60b to
deliver the sheet bundle has elapsed.
[0183] In the saddle stitch mode in the embodiment described above,
the stitching process and the folding process are consecutive. It
should be known that only the folding process can be performed
without the stitching process. Furthermore, the folded sheet bundle
device can stack thereon only the sheet bundles folded but not
stitched.
[0184] As described in detail above, the supplement guide member is
disposed on an upstream of the guide member guiding the sheet
bundle to the stitching position in the sheet bundle transport
direction. Such a feature is effective that when the sheet bundle
is fed to the stitching position, the sheet bundle can be led to
the guide member without the leading edge of the sheet bundle
touching an upstream of the guide member in the sheet bundle
transport direction. This assures of secure feed of the sheet
bundle and correct stitching.
[0185] Furthermore, when the stitching unit moves, the supplement
guide member is retracted to a position that does not interfere
with the movement of the stitching unit. Along with the movement
thereof, this configuration allows a wide area for the stitching
unit to stitch, without hindrance by the supplement guide member.
Also, this enables the stitching unit to be moved to a side
direction where it is easier to access and to replace staples.
[0186] While the invention has been explained with reference to the
specific embodiments of the invention, the explanation is
illustrative and the invention is limited only by the appended
claims.
* * * * *